Charge pump having AC and DC outputs for touch panel bootstrapping and substrate biasing

A charge pump configured to operate in a first mode and a second mode, the charge pump comprising:

• means for transferring a first direct current (DC) voltage to a first node;
• means for coupling a first output node to the first node;
• and
• means for coupling a second output node to the first node,
• wherein:
• during the first mode, the first output node is configured to output a second DC voltage based on the first DC voltage, and the second output node is configured to output a third DC voltage based on the first DC voltage, and
• during the second mode, the first output node is configured to output the second DC voltage based on the first DC voltage, and the second output node is configured to output an alternating current (AC) voltage, the AC voltage being offset by the third DC voltage.

A method of operating a charge pump in a first mode and a second mode, the method comprising:

• transferring a first direct current (DC) voltage to a first node;
• coupling a first output node to the first node;
• and
• coupling a second output node to the first node,
• wherein:
• during the first mode, the first output node is configured to output a second DC voltage based on the first DC voltage, and the second output node is configured to output a third DC voltage based on the first DC voltage, and
• during the second mode, the first output node is configured to output the second DC voltage based on the first DC voltage, and the second output node is configured to output an alternating current (AC) voltage, the AC voltage being offset by the third DC voltage.